Writing instrument



Nov. 6, 1951 l. CHESLER 2,573,691

WRITING INSTRUMENT Filed April 14, 1945 Q1 22. 158 Fa-*- ii n 16 20 4INVENTOR lsz'dofi ChesZefi BY r um I w ATTORNEYS 4M9 Patented Nov. 6,1951 UNITED STAT PATENT OFFICE WRITING INSTRUMENT Isidor Chesler,Oceanport, N. J., assignor to Eagle Pencil Company, a corporation ofDelaware Application April 14, 1945, Serial No. 588,382

Fig. 4 is a fragmentary cross-sectional view on a greatly enlarged scaleshowing the tip end of the. writing implement.

specific application shown in the drawings, is

concerned with writing implements, more particularly with what may bedesignated ink pencils. General objects of the invention are to providea liquid or paste dispenser, such as a writing implement, of simple,relatively inexpensive construction, which is substantially proofagainst flow stoppage on the one hand, or excessive flow, flooding orwaste, on the other, regardless of the temperature, humidity-oratmospheric pressure conditions under which the implement is being used,which in the writing implement embodiment requires substantially noservice or replacement, but inherently includes a sumcient supply of inkto last for years, which makes a line No. 574,498, filed January 25,1945, now issued that is substantially smudge-proof and requires noblotting, and which will write with substantially equal effectiveness,whether the writing surface is upright, or horizontal, above or belowthe writers hand.

The usual crimped tip edge for retaining in place the ball point ofwriting implements of the above type does not engage the ball at allpoints so that there is clearance at many points in the crimped edgethrough some of which air may enter the implement and through others inkescape therefrom, with fortuitous alternations of stoppage and excessink feed, difiiculties which would be aggravated were the ink in thebarrel maintained under relatively high propulsive pressure. Moreover,such crimped edge where it. does engage the ball surface acts like ascraper, so that excess ink that is not immediately conveyed to thepaper is scraped oil by said edge in the rolling of the ball and islater deposited upon the paper, intermittently rendering the writingstroke heavy and ragged.

Particular objects of the invention are to provide a smoothuninterrupted and secure bearing mount for the writing ball withoutundue restraint to the freedom of its rotation in use, which mount issufficiently tight to serve as a ball valve seat retaining the inkagainst leakage even though pressure of considerable magnitude besustained upon the ink in the barrel, which feeds the ink continuouslyand uniformly to the writin point and on the one hand avoids stop pageof ink flow due to the entry of air past the ball, and on the other handthe excess, flow Referring now to the drawings, a metal tip I0 ispreferably threaded at l2 into a frusto-conical section II which in turnis threaded at l3 into the barrel M of the writing implement. Theforward end of the tip mounts the writing ball I5 in manner to bedescribed hereinafter. The supply of ink is stored within the barrel,from which it may flow to the writing point in any or numerous ways.Preferably, the ink is main-. tained within the barrel under sustainedpropul sive pressure which is resisted by the ball writing point. Thepropulsive pressure may be exerted and sustained upon the ink in any ofvarious ways, as for instance by a spring according to the disclosure ofmy copending application Serial Patent No. 2,444,004, dated June 22,1948, but preferably the propulsive force is the atmospheric pressureexerted upon the incompressible column of ink in the barrel, as forinstance through a vent [6 in the barrel wall. The atmospheric pressuremay be exerted directly upon the ink exposed to the air, within thebarrel, suitable means being provided to preclude leakage of ink throughthe barrel vent, all as disclosed for instance in my copendingapplication Serial No. 577,773, filed February 14, 1945, now issuedPatent No. 2,504,649, issued April 18, 1950. Preferably, however, theatmospheric pressure is exerted through a flexible wall, desirably arubber sac, which insulates and protects the ink from exposure to theair. The atmospheric pressure being exerted substantially on the entireexposed wall of the sac causes the ball to be urged firmly against itsseat, thereby to preclude leakage. Particular embodiments of the latterarrangement, one of which is shown in Fig. 1 herein, are disclosed in mycopending application Serial No. 573,536, filed January 19, 1945, nowissued Patent 2,444,003. issued June 22, 1948.

Referring now to the writing end of the implement, the tip in ispreferably of stainless or cold rolled or machine steel and the ballhoused at its tip end is a solid sphere or ball l5 of hardened steel orhardened stainless steel which of ink with the escape of air from thetip, or the Fig. 3 is a transverse sectional detail view taken on line3-3 of Fig. 2,-and r g protrudes beyond the tip. The tip has a snuglyfitted area rather than line of contact with the ball in the region ofthe equator of the latter, that is, the bore of the tip engages the ballalong a spherical segment area extending from the equator e of the ballI5 outward toward the writing pole and preferably also inward toward theconfined pole of the ball. Desirably the area of contact is a sphericalsegment extending approximately equally at opposite sides of the equatorof the ball and in the preferred embodiment the total width of thatsegment is approximately 20 to 25 per cent of the diameter of the balluWhile those skilled in the art may conceive oi various ways ofconforming the tip for the "corre-- lation noted with respect to theball, a simple,

effective and reliable arrangement is to press the 1.

ball for snug fit into the end of the cylindrical tip bore, which latterfor that purpose may be of diameter in the order of .001- inch smallerthan v plement of the present invention an ink devoid that of the ball.Thereupon the tip is subjected to a swaging operation to cause thesofter metal thereof to flow into snug engagement with the equatorialzone of the ball along the width of spherical segment above set forth,thereby to form a smooth, polished spherical segment raceway 1' in thetip,'which snugly confines the ball.

Since the spherical segment raceway 1' at its outer rim is of diametersmaller than that of the ball, the ball is confined in place so that itcannot escape from the tip. The fit is so snug as to be substantiallyliquid tight but yet permits the ball to roll freely in any directionwithin its raceway in the writing operation.

In certain of the claims, the relation between the ball and itsspherical segment raceway in the 4 ball, which is altogether too-snugfor use with even the finest grade of pigment ink. For, the distancebetween the ball and its raceway is probably in the order of a micron orless and would act to strain out the pigment from the ink. It is,therefore, desirable to use with the writing imof pigment and that hassuitable dye in solution therein so that no solids are present to bestrained out at the raceway and the entire ink, including the vehicletogether with the color in solution therein, will be carried-by theball, but so sparingly as to dry substantially instantly upon thewriting sheet.

.The fit of the ball in its raceway is such that as long as the ball isstationary, no ink will flow orcreep from the pen. The greater thepressure transmitted through the ink, the more securely is the ballurged against its raceway which constitutes a smooth, thoroughlyeffective valve seat.

One particularly desirable way of accommodating the ink and exerting thesustained pressure thereon is shown in Fig. 1, which will be but brieflydescribed here, since this construction is the subject matter of mycopending application Serial No. 573,536, filed January 19, 1945, now

be removed after swaging the ball in place and formed as an integralpart of the tip,separating the axial bore l l of the tip from the ballcage [8, the bore and cage being preferably of about the same diameter,the cage diameter being shown but slightly smaller than that of thebore. Thus the ball is positioned by and rolls over the center IQ of thebarrier wall.

Communication from the bore I! to the ball cage 18 is preferablyeffected by way of a port, desirably itself a bore 20 of diametersmaller than the radius of the ball and towardone side of the ball seat,desirably as shown, nearly tan-' gentially of the tip bore l1. Desirablyonl one such bore 20 is used, for reasons which will appear more fullyin the description of the operation hereinafter.

. The rim 2| of the tip is preferably spaced from theball. This isaccomplished preferably by fashioning a peripheral groove 22 at theinterior periphery of the tip rim, the bottom of which groove 22 thuscoincides with the outer edge 23 ofthe segment ball raceway r.

, The tip and the ball may be of any of a wide range of diameters,depending upon the character of writing implement or other applicatorwith which the same is to be used. In a desirable ink pencil embodiment,the diameter of the ball l5 may be in the order of .04 inch, thediameter of the ball cage bore I8 as above noted may be about .001 inchless and the diameter of the port 20 in the order of .015 inch. Thewidth of the ball raceway 1 may be in the order of .008 inch. The ballpoint riding in a swage fitted raceissued Patent No. 2,444,003, issuedJune 22, 1948. According to this embodiment, there is housed within thebarrel M a flexible sac 25 which may be of thin rubber and which isnormally in collapsed condition, that is, it is preferably molded orelectroplated about a flat mandrel or core. so that it will distend tothe open position shown in Fig. 1, only when vacuum is externallyapplied thereto while the ink is introduced thereinto through thesection II before the tip ID has been applied, all in the manner setforth in the above entitled application. As will be seen, atmosphericpressure through the vent 18 in the barrel is applied over the entireouter surface area-of the flexible sac, which pressure is effec-- tivelysustained by the ball I5 in its raceway 1 so' that the port 20 and theannular space l8 below the raceway r in the ball cage 18 are completelyfilled with ink and no leakage will occur.

- In writing, as the ball rolls in the raceway, ink

from annular space 18 is entrained past the raceway. As ink is thusslowly consumed, the sustained atmospheric pressure upon the sac 25maintains the port 20 and ball cage l8 filled with ink. Should anyslight excess of ink be carried by the rolling ball l5 past the raceway1', as might occur in excessively warm weather, such ink will not bescraped off at the edge of the tip, but will accumulate in the annulartrough 22 Where it is held by capillarity and will be entrained inwardby the rolling ball l5 to return such excess ink to the interior of theball cage.

"'Were there any possibility for minute bubbles of air to enter therein,such bubbles would block the flow of ink until they have been againexpelled. The ink being pressure-propelled through the single small port20 and there being no other port'or passageway through which air canenter, no venting can occur, and there will be no intermittent stoppageof ink flow in the writing opera tion.

Thus there is adequate assurance that the implement will start writinginstantly when applied to the paper and will write under all conditionswith a continuous uninterrupted and uniform. line.

* While the invention is by no means limited to way, as disclosed,affords a passageway about th (i y p t c lar use as a Writ g i pl itlends itself particularly as a substitute for the familiar indelible orcopying pencil, since it makes an ink line and its point appliessufiicient pressure to make excellent carbon copies. It is also veryuseful for check signatures.

The teachings of the present invention may be advantageously applied byway of example as a leak-proof dispenser, combined with an applicatorfor cosmetics, such as lip rouge, mascara and perfume. Such cosmetics,preferably in viscous or pasty form, would be used within the barrel inplace of the ink in the implement above described, and the ball pointwould of course be of much larger diameter for ease of applicationwithout irritation to the delicate skin of the lips. The difiiculty ofmaking a lipstick soft enough for ready application, and yet solidenough not to melt in warm weather, the need for pointing the stick andfor providin a propel and repel case would all be obviated by thepresent invention.

The teachings of the present invention, when a suitably large point isused, are also applicable to paste and mucilage dispensers. Theinvention has the further advantage in such application, that the bodyof paste or mucilage is not exposed to the air, and so does not hardenor form an obstructing film on the contents of the dispenser as isinherently the case with conventional sqeegee and other rubber mouthmucilage tubes that operate on the principal of admitting air into thesystem to help feed out the paste.

As many changes could be made in the above construction, and manyapparently widely different embodiments of this invention could be madewithout departing from the scope of the claims, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. In a writing implement of the type having a metal ball writing pointprotruding therebeyond, the combination of a metal ball, a metal tipaccommodating said ball, said tip having a swage fit about oppositesides of the equator of the ball and afiording a smooth sphericalsegment raceway of curvature substantially equal to that of said ballfor and completely encircling the ball, and extending substantially tothe rim of said tip said rim having an annular trough therein adiacentthe ball for surplus ink.

2. In a writing implement of the type having a metal ball writing point,the combination of a metal ball, a metal tip accommodating said ball,said tip having a swage fit about the equator of the ball and affordinga smooth spherical segment raceway for the ball of curvaturesubstantially equal to that of said ball, said tip having in theinterior thereof a rigid backstop for the ball with a single porttherethrough laterally of the center of said backstop and of diameterless than the radius of the ball, through which ink passes to thesurfaces of the ball.

3. The combination recited in claim 2 in which the backstop is atransverse wall integral with and across the bore of the tip and inwhich the port is a bore therethrough of diameter less than half thediameter of said bore and nearly tangentially of said bore.

4. A writing implement comprising a vented barrel, a metal tip at theend of said barrel, a flexible sac in said barrel having one facethereof subjected to atmospheric pressure through the vent, ink chargingthe interior of the barrel between the other wall face of the sac andsaid tip, a ball writing point in the forward end of said tip, the metalfrom the forward rim of the tip being removed at the inner peripherythereof, to aiford an annular trough about the ball at the extremity ofthe tip, said tip having a sw-age fit about the equator of said ball andaffording a spherical segment raceway for the ball and fittingsufiiciently tightly to restrain leakage of ink therethrough under thesustained atmospheric pressure upon the ink.

5. A writing implement comprising a vented barrel having a writing tipthereon, a flexible ink filled sac within said barrel afiixed withrespect to said tip, said sac being of the normally collapsed type andbeing distended by its ink content, the tip having a bore therethrough,a ball lodged at the outer end of the tip, the outer rim of said tippresenting a groove along its inner periphery, with the outer part ofsaid groove spaced from the ball and affording an annular ink troughabout the ball, said tip having a swage fit about the equator of theball, along a smooth spherical segment raceway closely embracing theball, said fit being sufficiently tight to restrain the leakage of inkunder the sustained atmospheric pressure thereon.

ISIDOR CHESLER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 600,299 Werner Mar. 8, 1898807,280 Kegrize Dec. 12, 1905 1,065,872 Johnson June 24, 1913 1,171,652Riesberg Feb. 15, 1916 1,181,574 Crocker May 2, 1916 1,381,332 QualmannJune 14, 1921 1,485,181 Grund Feb. 26, 1924 1,527,971 Forsell Mar. 3,1925 1,616,551 Rosenberg Feb. 8, 1927 1,980,625 La Forest Nov. 13, 19342,096,397 Harris Oct. 19, 1937 2,106,046 Barlow Jan. 18, 1938 2,107,424Platt Feb. 8, 1938 2,208,588 Laforest Jan. 23, 1940 2,204,778 Sturm June18, 1940 2,211,312 Barlow Aug. 13, 1940 2,265,055 Biro Dec. 2, 19412,333,451 Sussman Nov. 2, 1943 2,376,222 Barlow 1- May 15, 19452,390,636 Biro Dec. 11, 1945 2,444,003 Chesler June 22, 1948 2,444,004Chesler June 22, 1948 FOREIGN PATENTS Number Country Date 366,218Germany 1923 476,971 Great Britain 1937 564,172 Great Britain Sept. 15,1944 564,173 Great Britain Sept. 15, 1944 OTHER REFERENCES Websters 1939Unabridged Dictionary-page 2290, definition 76 under set, page 2292,definition under set hammer.

